The present invention relates generally to dental implants and to the replacement of removed or broken teeth with artificial dental prostheses, and more particularly to the interconnection and adjustable alignment between the artificial dental implant and a dental prosthesis.
Whenever a natural tooth is lost, it is often possible to surgically implant an artificial replacement for the root of the lost tooth into the jawbone. These devices are commonly called dental implants. The function of these dental implants is to provide support for an artificial tooth or dental prosthesis, the implant thus functioning as an artificial root. Various devices are available to interconnect such implants with a dental prosthesis or an artificial tooth. Such interconnecting devices are commonly called dental implant inserts. These implant inserts are affixed into and extend upwardly from the dental implant that would normally protrude above the gum tissue into the oral cavity. Most modern dental implants are first surgically placed into the jawbone and, after a period of four to six months for healing, the implant insert is affixed to the dental implant. This allows the dental practitioner to be confident that the bony tissues have "osseointegrated" to the implant which is necessary for the biological success of the implant. At this time, an implant insert is attached to the dental implant by either threading engagement or cementation.
However, where a portion of the tooth remains within the jawbone, a cavity is prepared in the remaining tooth into which a suitable dental implant is embedded and secured.
A number of such dental implants are known to applicant as follows:
______________________________________ #4,252,525 Child #4,671,768 Ton #4,270,905 Mohammed #4,195,409 Child #3,797,113 Brainin #3,717,932 Brainin #3,629,943 Gindea ______________________________________
Two additional unpatented dental implants, typically, are known to applicant and distributed by Whaledent, International under their trademarks TRIAX and PARA POST PLUS.
Additionally, artificial dentures or prostheses have been patented as disclosed in U.S. Pat. No. 3,343,262 to Burg and in U.S. Pat. No. 4,318,696 to Casama.
Implant inserts presently available, however, do not adequately address certain problems associated with fabrication of artificial teeth and/or a dental prosthesis associated with dental implants. With regard to dental prostheses, ideally, dental implants and their associated implants insert should be positioned parallel with adjacent natural teeth and also positioned parallel with other implants that may be required. Unfortunately, such needed parallelism is often difficult to attain because of anatomical considerations within the jawbone, loss of excess bone, and a common presence of misaligned natural teeth. As a result of these conditions, it is often desirable for the dental practitioner to be able to vary the angle between the implant axis of the dental insert and that of the dental insert, thus achieving needed parallelism. It is therefore extremely useful that the dental practitioner have the ability to easily vary this angular relationship between the implant and the implant insert at the time that the implant insert is attached to the previously permanently secured and positioned dental implant.
Two methods of attaching an implant insert to a permanently secured dental implant are presently available. The first is by cementation of the implant insert into the implant while the second method is by threadable engagement of the implant insert within the implant. The only method known to applicant, a practicing dentist (D.D.S.), for accommodating misaligned installation of the implant insert dental prostheses is to individually fabricate the interconnecting structure between dental implant and dental prosthesis or to substantially deform presently available means for interconnecting these two components prior to, or after, installation into the dental implant.
A further difficulty with regard to threaded implant inserts is that, if the dental practitioner must manually modify it to accommodate angular misalignment, it is extremely difficult to determine the exact rotational relationship between the implant and the implant insert when they are secured tightly together unless the final rotational relationship is established prior to deforming the implant insert or fabricating a custom implant insert.
It is here emphasized that, throughout this disclosure, the term "dental implant" or "implant" includes those devices which are securable within the remaining root portion of a tooth, as well as those devices which are intended to fully replace all tooth root material and to be "osseointegranted" into the jawbone. Therefore, my invention is equally applicable to both types of implants.
The present invention provides a universal dental prosthesis retention system which conveniently allows the dental practitioner to universally adjust the angular misalignment between the longitudinal axes of the dental implant and the implant insert and, thereafter, to securely lock this nonaligned arrangement for receipt of the dental prosthesis atop the prosthesis insert portion of the invention.